On 2012/11/27 10:38, Tang Chen wrote: > On 11/27/2012 09:08 AM, Hanjun Guo wrote: >> On 2012/11/26 14:06, Tang Chen wrote: >>> On 11/26/2012 01:42 PM, Hanjun Guo wrote: >>>> >>>> Hi all, >>>> I think Yasuaki mentioned the key point for the container device remove, >>>> that is dependency. >>>> >>>> Currently, container, processor, and memory hotpulg are managed by different ACPI >>>> hotplug drivers, the driver works when handle device hotplug individually, but they >>>> have no idea for each other. >>>> >>>> This may introduce some issues, such as Yasuaki mentioned above, that is to say, we >>>> should remove its child before remove the device itself, and hot add its parent before >>>> the device itself. >>>> >>>> According to the ACPI namespace, we can resolve most of dependency issues. On a typical >>>> two processor sockets system, the namespace is like this: >>>> >>>> /_SB ---container device, with HID ACPI0004 >>>> |_SCK0 ---container device, with HID ACPI0004 >>>> |_CPU0 ---processor device, with HID ACPI0009 or LNXCPU >>>> |_... >>>> |_CPUx >>>> |_MEM0 ---Memory device, with HID PNP0C80 >>>> |_SCK1 >>>> |_CPU0 >>>> |_... >>>> |_CPUx >>>> |_MEM1 >>>> |_PCI0 ---Host bridge, with HID PNP0A03 or PNP0A08 >>>> >>>> If hot remove the container device, such as SCK0, we can easily know the dependency list >>>> is CPU0~CPUx and MEM0, but I think the ACPI hotplug driver haven't resolve this now. >>>> >>>> And there is another corner case for hotplug devices in the namespace above, that is: >>>> 1) Remove SCK0. yes, we can remove it with no dependency to the host bridge PCI0; >>>> >>>> 2) Remove SCK1 after SCK0. we should remove the host bridge PCI0 first, >>>> or the system will crash down. yes, dynamic dependency analysis is needed here. >>>> and the ACPI hotplug driver totally have no idea of this. >>>> >>>> so, should we do something to settle this down ? >>> >>> Hi Guo, >>> >>> I am trying to do this too. :) >> >> Great， what's your idea of this? >> > Hi Guo, > > I noticed they had a lot of discussion on this topic. > https://lkml.org/lkml/2012/11/15/159 > > And Vasilis's latest patches are here: > https://lkml.org/lkml/2012/11/23/335 > > I think we can have a review of this patchset first. :) Hi Tang, Thanks for your remind, I will review Vasilis's latest patches, and reply Vasilis's patch if I have any comments. > > And also, as you said, the new ACPI hotplug framework from Liu Jiang > will settle this problem more properly. > So I think any solution now could be temporary. :) > > . > -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
